sync.Cond demonstration

condition_test.go

package main

import (
	"fmt"
	"sync"
	"time"
)

func main() {
	nConnections := 10

	var wg sync.WaitGroup
	wg.Add(nConnections)
	cond := sync.NewCond(&sync.Mutex{})

	for i := 0; i < nConnections; i++ {
		go func(i int) {
			fmt.Println("Before lock ", i)
			cond.L.Lock()
			fmt.Println("Before wait ", i)
			cond.Wait()

			fmt.Println("Here i am", i)

			cond.L.Unlock()
			fmt.Println("After unlock ", i)
			wg.Done()
		}(i)
	}

	fmt.Println("Sleeping...")
	time.Sleep(time.Second * 1)
	fmt.Println("Storm!")

	cond.Broadcast()
	wg.Wait()
}